let regexp = /t(e)(st(\d?))/g;
let str = 'test1test2';

let array = [ ...str.matchAll ( regexp ) ];
debugger;
console.log ( array[0] );
// expected output: Array ["test1", "e", "st1", "1"]

console.log ( array[1] );
// expected output: Array ["test2", "e", "st2", "2"]
